This may sound like a dumb question but what exactly is the difference between the 02-03 wrx and 04+ suspension. Every time i look for some coilovers they say they only fit 02-03 so i just want to know what the difference is between the years.

 

02-03 has a different rear top hat. this makes the springs different on the model years.

 

In '04, they also changed the rear sway bar bushing style and bracket (beefier). This affects sway bar applications as well, because obviously the bushing changed in '04, though the bars are still interchangeable.